WO 2016/156000 A2 discloses a method for operating a laser activated light source and a corresponding light converter. The light converter comprises a light converting layer with a sensor functionally integrated with the light converting layer. The sensor comprises a pattern of conductive layers being arranged in the emission path of light generated by means of the light converter. A laser radiation is adjusted in accordance with a detection of a condition of the light converting layer by measurement of the sensor.
The safety functionality of the sensor does not cover all failure modes and reduces efficiency of the laser activated light source.
DE102014214601A1 and DE102016207759A1 describe safety mechanisms for static laser beams where one or more sensors receive a small part of the laser light having passed the light converter. DE102014214601A1 and embodiments of DE102016207759A1 use a polarized laser source and use the fact that the light converter will destroy such polarization. I.e., by the sensor only being sensitive for laser light of original polarization, such sensor signal can detect sufficiently large defects of the light converter. Alternatively or in addition, DE102016207759A1 foresees a sensor array whose signals are compared to each other, so contributing spatial resolution of which location of the light converter the laser light stems from.